REMOVAL OF ARSENIC FROM ARSENIC-CONTG. FERROUS SULFATE SOLUTION

摘要

PURPOSE:To efficiently remove arsenic with simplified operation, by adding calcium carbonate to a solution containing at least arsenic and ferrous sulfate, and then aerating the solution to adsorb or coprecipitate arsenic with formed precipitate. CONSTITUTION:Calcium carbonate is previously added to a solution containing at least arsenic and ferrous sulfate, and said ferrous sulfate is gradually oxidized and partially converted into ferric sulfate by aerating the solution. The ferric sulfate is immediately neutralized by calcium carbonate and formed into iron precipitate. Hence, arsenic in the liquid is efficiently adsorbed and coprecipitated with the iron precipitate. The oxidation Fe2+ Fe3+ is performed little by little, and the formed ferric sulfate is neutralized and precipitated with the preadded calcium carbonate. Since pH for the neutralizing reaction can be raised at about 6, arsenate is easily precipitated and deposited, and the adsorption-coprecipitation effect of arsenic to the formed iron precipitate is excellent.